The anomaly is above two EM conductors and was outlined in a 140-hole auger program on a 200 by 50-metre grid around an historical reverse circulation (RC) hole which returned 2 metres at 2.13% zinc and 0.39% lead.
Auger drilling covered 600 metres of strike in either direction from the RC hole and the results have prompted Great Boulder to plan further testing during the 2020 field season.
Review highlights intersection
The decision to follow-up in this area followed a review of Mt Venn project which highlighted the anomalous RC intersection had not been revisited.
This hole intersected 12 metres at 0.8% zinc, 3.3 g/t silver and 0.16% lead from 48 metres, including 2 metres at 2.13% zinc, 3.56 g/t silver and 0.39% lead from 58 metres.
It is 900 metres north of the nearest copper-nickel sulphide mineralisation at Mt Venn and the mineral assemblage is different to previous sulphide intersections in the area.
Red-orange sphalerite is intergrown with subordinate galena and chalcopyrite contrasting to the typical Mt Venn sulphides of pyrrhotite and chalcopyrite.
The anomaly is 900 metres north of previous copper-nickel intersections at Mt Venn with DHEM conductor plates shown in yellow.
Further work needed
The prospect requires further drilling and/or ground EM surveys to determine its significance.
Putting the auger program findings in context, the Mt Venn area has a thin layer of soil over a stripped weathering profile, meaning there is only a shallow depth from surface to fresh rock.
Previous drilling has identified that silver, zinc and lead are typically depleted within the soil profile.
Down-hole EM surveys carried out during the 2017 program identified two off-hole EM conductor plates which have not yet been tested by drilling.
All EM plates tested at Mt Venn to date are the result of massive sulphides, with no conductors being caused by graphitic shales or conductive groundwater.
Great Boulder’s planned work is expected to begin in March-April 2020 and will be undertaken in conjunction with other work already scheduled at the nearby Winchester and Mt Carlon projects.
With a focus on base metals and gold, the company has a range of projects from greenfields through to advanced exploration, including Mt Venn and Winchester copper-nickel-cobalt projects and Whiteheads Gold Project.